<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>基本数据类型传参</title>
  <script>
    // 简单数据类型传参
    function fn (a) {
      a++
      console.log(a)   // 11
    }

    var x = 10
    fn(x)
    console.log(x)   // 10
  </script>
</head>
<body>

</body>
</html>